Best Way to animate lake
For a large rippling body of water such as a lake, rather than use a fluid simulation (which would require a great deal of simulation time to get believable results) you can combine multiple waves to give the effect of ripples on the surface of the fluid - similar to that in this answer. However, if you don't need it to be seamless, you can use Wave textures instead of plain Sine waves with the Distortion significantly increased - this will reduce the number of waves you need to combine to get a believable result.

For example, consider the following material :



Here, two Wave textures with high noise are combined via an Add maths node and used to drive the Bump of a flat plane. Note that one of the Wave textures has been rotated via the Mapping node.

The Value node is keyframed to vary the offset of the Wave textures - to move the waves 'forward' as the animation progresses.

By adjusting the rotation, Scale, and other Texture parameters you can get quite a pleasing effect as follows :



Note that this is using the Bump node to generate the Normal. If the water will be viewed from a very shallow angle it may be preferable to add geometry and use True Displacement to create actual waves in the mesh.